[66631] in North American Network Operators' Group
Re: One-element vs two-element design
daemon@ATHENA.MIT.EDU (Petri Helenius)
Sun Jan 18 02:57:14 2004
Date: Sun, 18 Jan 2004 09:55:44 +0200
From: Petri Helenius <pete@he.iki.fi>
To: Eric Kuhnke <eric@fnordsystems.com>
Cc: nanog@merit.edu
In-Reply-To: <4009C3FE.6080601@fnordsystems.com>
Errors-To: owner-nanog-outgoing@merit.edu
Eric Kuhnke wrote:
>
>
> Last year, a Boeing in flight over the middle of the pacific ocean had
> its entire glass cockpit system go dark. After frantic conversation
> with the air traffic controllers a decision was made to toggle the
> circuit breakers for the TRIPLE-REDUNDANT computer system onboard,
> which brought back the displays. Even with a 2+1 setup, things can
> still go wrong...
>
>
Most, if not all, redundant systems have a single instance of
synchronization protocol.
One significant vendor of packet forwarding gear was known for hanging
the secondary
RP almost every time when the primary failed. The hang was usually
associated with
chatter failing with the failed card :-)
Pete
